<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
          #fa{
              width: 200px;
              height: 200px;
              background-color: red;
          }
          .box  {
              width: 100px;
              height: 100px;
              background-color: green;
              display: none;
          }
    </style>
</head>
<body>
    <div id="fa">
        <div class="box"></div>
    </div>
</body>
</html>
<script src="./jquery-1.12.2.js"></script>
<script>
    $(function(){
       $('#fa').click(function(){
           console.log('1');
           
           $('.box').show();

       })
    })
</script>